Devices And Methods For Wireless Signaling And Wireless Power Transmission

ABSTRACT

Devices, methods and computer readable media relating to wireless signaling and wireless power transmission. A method according to the present technology may include the step of sensing a power of the wireless signal received via a plurality of antennas from a device positioned in a wireless signaling environment. The method may include the step of transducing energy of the wireless signal to an electric current. The method may include the step of adjusting a voltage of the electric current according to the sensing.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. Pat. Application No.17/243,579 filed on Apr. 29, 2021, and now allowed; which is acontinuation of 15/384,250, filed Dec. 19, 2016, and issued as U.S. Pat.No. 11,031,822 on Jun. 8, 2021; which is a continuation of U.S. Pat.Application No. 15/354,998, filed Nov. 17, 2016, and issued as U.S. Pat.No. 9,866,074 on Jan. 9, 2018; which claims priority to U.S. ProvisionalApplication No. 62/256,694 filed Nov. 17, 2015; each of which isincorporated by reference herein in its entirety.

BACKGROUND

Many portable electronic devices are powered by batteries. Rechargeablebatteries are often used to avoid the cost of replacing conventionaldry-cell batteries and to conserve resources. However, rechargingbatteries with conventional rechargeable battery chargers requiresaccess to an alternating current (AC) power outlet, which is sometimesnot available or not convenient.

Accordingly, a need exists for technology that overcomes the problemdemonstrated above, as well as one that provides additional benefits.Other limitations of existing or prior systems will become apparent tothose of skill in the art upon reading the following DetailedDescription.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a diagram illustrating a wireless power delivery environmentin accordance with implementations of the disclosed technology.

FIG. 2 is a sequence diagram illustrating operations between a wirelesstransmitter and a power receiver client for commencing wireless powerdelivery.

FIG. 3 is a block diagram illustrating a wireless power receiver inaccordance with implementations of the disclosed technology.

FIG. 4 is a system overview diagram in accordance with implementationsof the disclosed technology.

FIG. 5 is a schematic block diagram illustrating circuit components fortransmitting wireless power and receiving communication signals from aclient device in accordance with implementations of the disclosedtechnology.

FIG. 6 is a schematic block diagram illustrating an antenna managementunit (AMU) from FIG. 5 in more detail in accordance with implementationsof the disclosed technology.

FIG. 7 is a schematic integrated circuit block diagram of multiple AMUsfor transmitting wireless power and receiving signals from a clientdevice in accordance with implementations of the disclosed technology.

FIG. 8 is another schematic integrated circuit block diagram fortransmitting wireless power and receiving signals from a client devicein accordance with implementations of the disclosed technology.

FIG. 9 is an alternative schematic integrated circuit block diagram fortransmitting wireless power and receiving signals from a client deviceusing an AMU in the digital domain integrated circuit.

FIG. 10 is an illustration of a beacon timing and power deliveryschedule for transmitting wireless power in accordance withimplementations of the disclosed technology.

FIG. 11 is a schematic illustration of an AMU with a client devicenumber and corresponding phase for a client device that can be used intransmitting wireless power to a client device in accordance withimplementations of the disclosed technology.

FIG. 12 is an example of a power delivery table for client devices froman AMU in accordance with implementations of the disclosed technology.

FIGS. 13A-C collectively are a schematic integrated circuit blockdiagram for a receiver that can be used for receiving wireless power ata client device in accordance with implementations of the disclosedtechnology.

FIG. 14 is another schematic integrated circuit block diagram for areceiver that can be used for receiving wireless power at a clientdevice in accordance with implementations of the disclosed technology.

FIG. 15 is yet another schematic integrated circuit block diagram for areceiver that can be used for receiving wireless power at a clientdevice in accordance with implementations of the disclosed technology.

FIG. 16 is a schematic integrated circuit block diagram for a receiverused to for receive wireless power at the client device, where thereceiver is connected to a central processing unit in the client devicein accordance with implementations of the disclosed technology.

FIG. 17 is a schematic integrated circuit block diagram for a receiverto receive wireless power at a client device, where the receiver isconnected to a wireless communication circuit in the client device inaccordance with implementations of the disclosed technology.

DETAILED DESCRIPTION

The disclosed technology relates to wireless communication and wirelesspower transmission. In some implementations, the disclosed technologyincludes a wireless power delivery system with a charger and receiver.The charger can detect the location of the receiver, where the receiveris physically coupled to a client device (e.g., smart phone). Thecharger can also transmit radio frequency (RF)-based wireless power tothe receiver based on the detected location of the receiver. The chargerincludes an integrated circuit for transmitting wireless power andreceiving location information from a client device. Similarly, thereceiver includes an integrated circuit for receiving wireless power andtransmitting location information to the charger. The integratedcircuits for the charger and receiver are described in further detailherein (e.g., in FIGS. 5-17 ).

The Detailed Description includes three sections. Section I, titled“System Overview and Architecture,” describes the wireless powerdelivery system with the charger and the receiver. Section II, titled“Charger Chip Technology,” describes an integrated circuit that can beincorporated into the charger. Section III, “Client Chip Technology,”describes an integrated circuit for the receiver. The integratedcircuits described in Sections II and III can be incorporated into thetechnology disclosed in Section I.

The following description and drawings are illustrative, and are not tobe construed as limiting. Numerous specific details are described toprovide a thorough understanding of the disclosure. However, in certaininstances, well-known or conventional details are not described in orderto avoid obscuring the description. References to “one” or “an”embodiment in the present disclosure can be, but are not necessarily,references to the same embodiment, and such references mean at least oneof the embodiments.

Reference in this specification to “one embodiment” or “an embodiment”means that a particular feature, structure, or characteristic describedin connection with the embodiment is included in at least one embodimentof the disclosure. The appearances of the phrase “in one embodiment” invarious places in the specification are not necessarily all referring tothe same embodiment, nor are separate or alternative embodimentsmutually exclusive of other embodiments. Moreover, various features aredescribed which may be exhibited by some embodiments and not by others.Similarly, various requirements are described which may be requirementsfor some embodiments but not other embodiments.

The terms used in this specification generally have their ordinarymeanings in the art within the context of the disclosure and in thespecific context where each term is used. Certain terms that are used todescribe the disclosure are discussed below, or elsewhere in thespecification, to provide additional guidance to the practitionerregarding the description of the disclosure. For convenience, certainterms may be highlighted, for example, using italics and/or quotationmarks. The use of highlighting has no influence on the scope and meaningof a term; the scope and meaning of a term is the same, in the samecontext, whether or not it is highlighted. It will be appreciated thatthe same thing can be said in more than one way.

Consequently, alternative language and synonyms may be used for any oneor more of the terms discussed herein, and no special significance ismeant when a term is elaborated upon herein. Synonyms for certain termsare provided. A recital of one or more synonyms does not exclude the useof other synonyms. The use of examples anywhere in this specification,including examples of any terms discussed herein, is illustrative only,and is not intended to further limit the scope and meaning of thedisclosure or of any term. Likewise, the disclosure is not limited tovarious embodiments given in this specification.

Without intent to further limit the scope of the disclosure, examples ofinstruments, apparatus, methods and their related results according tothe embodiments of the present disclosure are given below. Note thattitles or subtitles may be used in the examples for convenience of thereader and in no way limit the scope of the disclosure. Unless otherwisedefined, all technical and scientific terms used herein have the samemeaning as commonly understood by one of ordinary skill in the art towhich this disclosure pertains. In the case of conflict, the presentdocument, including definitions, will control.

The techniques described herein utilize wireless technologies to deliverpower, data, or both. In some embodiments, power, data, or both, may bedelivered simultaneously as a continuous complex waveform, as a pulsedwaveform, as multiple overlapping waveforms, or combinations orvariations thereof. The power and data may be delivered using the sameor different wireless technologies.

The wireless technologies described herein may apply to not onlyelectromagnetic (EM) waves, but also to sound waves, and/or other formsof periodic excitations (e.g., phonons). EM waves may include radiowaves, microwaves, infrared radiation, visible light, ultravioletradiation, X-rays, and/or gamma rays. Sound waves may include infrasoundwaves, acoustic waves, and/or ultrasound waves. The techniques describedherein may simultaneously utilize multiple wireless technologies and/ormultiple frequency spectrums within a wireless technology to deliver thepower, data, or both.

The wireless technologies may include dedicated hardware components todeliver power and/or data. The dedicated hardware components may bemodified based on the wireless technology, or a combination of wirelesstechnologies, being utilized. For example, when applied to sound waves,the system employs microphones and speakers rather than antennas.

System Overview and Architecture

FIG. 1 is a diagram illustrating a wireless communication/power deliveryenvironment 100 in accordance with implementations of the disclosedtechnology. More specifically, FIG. 1 illustrates the wireless powerdelivery environment 100 in which wireless power and/or data can bedelivered to available wireless devices 102.1-102.n (also referred to as“client devices”) having one or more power receiver clients 103.1-103.n(also referred to herein as “wireless power receivers”, “wireless powerclients”, or “receivers”). The wireless power receivers are configuredto receive wireless power from one or more wireless transmitters 101.

As shown in FIG. 1 , the wireless devices 102.1-102.n are mobile phonedevices 102.2 and 102.n, respectively, and a wireless game controller102.1, although the wireless devices 102.1-102.n can be any (smart ordumb) wireless device or system that needs power and is capable ofreceiving wireless power via one or more integrated power receiverclients 103.1-103.n. Smart devices are electronic devices that cancommunicate (e.g., using WiFi) and transmit beacon signals. Dumb devicesare electronic devices that are passive devices that may not communicate(e.g., no Bluetooth or Wi-Fi capability) and may not transmit a beaconsignal. As discussed herein, the one or more integrated power receiverclients or “wireless power receivers” receive and process power from oneor more transmitters/transmitters 101.a-101.n and provide the power tothe wireless devices 102.1-102.n for operation thereof.

Each transmitter 101 (also referred to herein as a “charger”, “array ofantennas” or “antenna array system”) can include multiple antennas 104,e.g., an antenna array including hundreds or thousands of spaced-apartantennas, that are each capable of delivering wireless power to wirelessdevices 102. Each transmitter 101 may also deliver wirelesscommunication signals to wireless devices 102. In some embodiments, thewireless power and wireless communication signals may be delivered as acombined power/communication signal. Indeed, while the detaileddescription provided herein focuses on wirelessly transmitting power,aspects of the invention are equally applicable to wirelesslytransmitting data.

In some embodiments, the antennas are adaptively-phased RF antennas andthe transmitter 101 utilizes a novel phase shifting algorithm asdescribed in one or more of U.S. Pat. Nos. 8558661, 8159364, 8410953,8446248, 8854176, U.S. Pat. Application Nos. 14/461,332 and 14/815,893,which are hereby incorporated by reference in their entireties. Thetransmitter 101 is capable of determining the appropriate phases todeliver a coherent power transmission signal to the power receiverclients 103. The array is configured to emit a signal (e.g., continuouswave or pulsed power transmission signal) from multiple antennas at aspecific phase relative to each other.

Additionally, the transmitter 101 may include a time delayed retrodirective RF holographic array that delivers wireless RF power thatmatches the client antenna patterns in three dimensional (3D) space(polarization, shape, & power levels of each lobe). It is appreciatedthat use of the term “array” does not necessarily limit the antennaarray to any specific array structure. That is, the antenna array doesnot need to be structured in a specific “array” form or geometry.Furthermore, as used herein the term “array” or “array system” may beused include related and peripheral circuitry for signal generation,reception, and transmission, such as radios, digital logic, and modems.

The wireless devices 102 can include one or more power receiver clients103 (also known as a “wireless power receiver”). As illustrated in theexample of FIG. 1 , power delivery antennas 104 a and data communicationantennas 104 b are shown. The power delivery antennas 104 a areconfigured to provide delivery of wireless power in the wireless powerdelivery environment. The data communication antennas are configured tosend data communications to, and receive data communications from, thepower receiver clients 103.1-103.n and/or the wireless devices102.1-102.n. In some embodiments, the data communication antennas cancommunicate via Bluetooth™, WiFi, ZigBee™, or other wirelesscommunication protocols.

Each power receiver client 103.1-103.n includes one or more antennas(not shown) for receiving signals from the transmitters 101. Likewise,each transmitter 101.a-101.n includes an antenna array having one ormore antennas and/or sets of antennas capable of emitting continuouswave signals at specific phases relative to each other. As discussedabove, each array is capable of determining the appropriate phases fordelivering coherent signals to the power receiver clients 103.1-103.n.For example, coherent signals can be determined by computing a complexconjugate of a received beacon signal at each antenna of the array suchthat the coherent signal is properly phased for the particular powerreceiver client that transmitted the beacon signal, though coding otherthat use of the complex conjugate may be used. The beacon signal, whichis primarily referred to herein as a continuous waveform, canalternatively or additionally take the form of a modulated signal.

Although not illustrated, each component of the environment, e.g.,wireless power receiver, transmitter, etc., can include control andsynchronization mechanisms, such as a data communication synchronizationmodule. The transmitters 101.a-101.n are connected to a power sourcesuch as, for example, a power outlet or source connecting thetransmitters to a standard or primary alternating current (AC) powersupply in a building. Alternatively or additionally, one or more of thetransmitters 101.a-101.n can be powered by a battery or via other powerproviding mechanism.

In some embodiments, the power receiver clients 103.1-103.n and/or thetransmitters 101.a-101.n utilize or encounter reflective objects 106such as, for example, walls or other RF reflective obstructions withinrange to beacon and deliver and/or receive wireless power and/or datawithin the wireless power delivery environment. The reflective objects106 can be utilized for multi-directional signal communicationregardless of whether a blocking object is in the line of sight betweenthe transmitter and the power receiver client.

As described herein, each wireless device 102.1-102.n can be any systemand/or device, and/or any combination of devices/systems that canestablish a connection with another device, a server, and/or othersystems within the example environment 100. In some embodiments, thewireless devices 102.1-102.n include displays or other outputfunctionalities to present data to a user and/or input functionalitiesto receive data from the user. By way of example, a wireless device 102can be, but is not limited to, a video game controller, a serverdesktop, a desktop computer, a computer cluster, a mobile computingdevice such as a notebook, a laptop computer, a handheld computer, amobile phone, a smart phone, a battery or component coupled to abattery, a PDA, a wearable electronic device, a light fixture,electrical device embedded in a system (e.g., automobile), etc. Thewireless device 102 can also be any wearable device such as watches,necklaces, rings, or even devices embedded on or within the customer.Other examples of a wireless device 102 include, but are not limited to,safety sensors (e.g., fire or carbon monoxide), electric toothbrushes,electronic door locks/handles, electric light switch controllers,electric shavers, etc.

Although not illustrated in the example of FIG. 1 , the transmitter 101and the power receiver clients 103.1-103.n can each include a datacommunication module for communication via a data channel. Alternativelyor additionally, the power receiver clients 103.1-103.n can direct thewireless devices 102.1-102.n to communicate with the transmitter viaexisting data communications modules.

FIG. 2 is a sequence diagram 200 illustrating example operations betweena wireless transmitter 101 and a power receiver client 103 forcommencing wireless power delivery, according to an embodiment.Initially, communication is established between the transmitter 101 andthe power receiver client 103, such as communication via Bluetooth™,WiFi, ZigBee™, or other wireless communication protocols. Thetransmitter 101 subsequently sends a beacon schedule to the powerreceiver client 103 to arrange beacon broadcasting and RF power/datadelivery schedules with this and any other power receiver clients. Basedon the schedule, the power receiver client 103 broadcasts the beacon. Asshown, the transmitter 101 receives the beacon from the power receiverclient 103 and detects the phase (or direction) at which the beaconsignal was received. The transmitter 101 then delivers wireless powerand/or data to the power receiver client 103 based on the phase (ordirection) of the received beacon. That is, the transmitter 101determines the complex conjugate of the phase and uses the complexconjugate to deliver power to the power receiver client 103 in the samedirection in which the beacon signal was received from the powerreceiver client 103.

In some embodiments, the transmitter 101 includes many antennas; one ormore of which are used to deliver power to the power receiver client103. The transmitter 101 can detect phases of the beacon signals thatare received at each antenna. The large number of antennas may result indifferent beacon signals being received at each antenna of thetransmitter 101. The transmitter may then utilize the algorithm orprocess described in one or more of U.S. Pat. Nos. 8558661, 8159364,8410953, 8446248, 8854176, and U.S. Provisional Pat. Application Nos.62/146,233 and 62/163,964, which are hereby incorporated by reference intheir entireties. The algorithm or process determines how to emitsignals from one or more antennas that takes into account the effects ofthe large number of antennas in the transmitter 101. In other words, thealgorithm determines how to emit signals from one or more antennas insuch a way as to create an aggregate signal from the transmitter 101that approximately recreates the waveform of the beacon, but in theopposite direction.

The transmitter 101 can include a housing structure. The housingstructure is disclosed in more detail U.S. Pat. Application 15/289,117,titled “ANTENNA CONFIGURATIONS FOR WIRELESS POWER AND COMMUNICATION, ANDSUPPLEMENTAL VISUAL SIGNALS,” which is hereby incorporated by referencein its entirety. As disclosed in the application, the transmitter 101 ismoveable. Moveable generally means the transmitter can be readily liftedby a human and moved to another location (e.g., in a room). In someimplementations, the transmitter 101 can be plugged into a standard 12 Voutlet in home or commercial structure.

FIG. 3 is a block diagram illustrating an example receiver 300 inaccordance with implementations of the disclosed technology. Thereceiver 300 includes various components including control logic 310,battery 320, communication block 330 and associated antenna 370, powermeter 340, rectifier 350, beacon signal generator 360 and an associatedantenna 380, and switch 365 connecting the rectifier 350 or the beaconsignal generator 360 to an associated antenna 390. Some or all of thecomponents can be omitted in some embodiments. Additional or fewercomponents are also possible.

The rectifier 350 receives (via one or more client antennas) the powertransmission signal from the power transmitter, which is fed through thepower meter 340 to the battery 320 for charging. The power meter 340measures the total received power signal strength and provides thecontrol logic 310 with this measurement. The control logic 310 also mayreceive the battery power level from the battery 320 itself or receivebattery power data from, e.g., an API of an operating system running onthe receiver 300. The control logic 310 may also transmit/receive, viathe communication block 330, a data signal on a data carrier frequency,such as the base signal clock for clock synchronization. The beaconsignal generator 360 transmits the beacon signal, or calibration signal,using either the antenna 380 or 390. It may be noted that, although thebattery 320 is shown for being charged and for providing power to thereceiver 300, the receiver may also receive its power directly from therectifier 350. This may be in addition to the rectifier 350 providingcharging current to the battery 320, or in lieu of providing charging.Also, it may be noted that the use of multiple antennas is one exampleof implementation and the structure may be reduced to one sharedantenna, where the receiver multiplexes signal reception/transmission.

An optional motion sensor 395 detects motion and signals the controllogic 310. For example, when a device is receiving power at highfrequencies above 500 MHz, its location may become a hotspot of(incoming) radiation. So when the device is on a person, the level ofradiation may exceed a regulation or exceed acceptable radiation levelsset by medical/industrial authorities. To avoid any over-radiationissue, the device may integrate motion detection mechanisms such asaccelerometers, assisted GPS, or other mechanisms. Once the devicedetects that it is in motion, the disclosed system assumes that it isbeing handled by a user and signals the power transmitting array eitherto stop transmitting power to it, or to lower the received power to anacceptable fraction of the power. In cases where the device is used in amoving environment like a car, train, or plane, the power might only betransmitted intermittently or at a reduced level unless the device isclose to losing all available power.

FIG. 4 is a system overview in accordance with implementations of thedisclosed technology. As shown, among other features, in someembodiments, the wireless power receiver can be in a form of anapplication specific integrated circuit (ASIC) chip, a mobile phonecase, in a display device (e.g. computer monitor or television, which inturn may relay power to a nearby receiver 103), packaged within astandard battery form factor (e.g. AA battery), etc.

FIGS. 5-17 are schematic/block diagrams that depict suitableimplementations of the invention. These Figures generally useconventional symbols and nomenclature, and thus, similar symbols andnomenclature have similar or identical functions. Certain circuitelements represented by possibly less familiar symbols or nomenclatureare discussed herein in more detail. Without sacrificing clarity, butfor brevity, and to orient one skilled in the art, certain portions ofthe Figure will be discussed in detail. From the detailed discussions ofcertain portions and circuit elements of the Figures, one skilled in therelevant art can readily understand how to practice aspects of theinvention.

Charger Chip Technology

As described above in FIGS. 1-4 , the transmitter can transmit wirelesspower to a client device. To transmit wireless power to the clientdevice, the transmitter can use a charger chip or multiple chargerchips. The charger chip receives a beacon signal from a receiverelectrically coupled to the client device and uses the beacon signal forcomputing the location of the client device. Based on the computedlocation of the client device, the charger chip transmits RF-basedwireless power to the client device using a transceiver, antenna port,phase detector, and phase shifter. More generally, the charger chip isconsidered a multiple input and multiple output transceiver thatimplements at least two functions: detecting the location of clientdevices and subsequently transmitting focused power to the clientdevices.

The charger chip can be composed of semiconductor material, such asSilicon, GaAs, Silicon on an insulator (SOI), or GaN. Manufacturers canfabricate the charger chip using semiconductor material and processingmethods such as doping, ion implantation, etching, deposition of variousmaterials, photolithographic patterning, dicing, and/or packaging. Insome implementations, the charger chip is an ASIC. One or more chargerchip ASICs can be integrated into the transmitter 101 shown in FIG. 1 .

In some implementations, the charger chip can be electrically coupled toa processing unit in the transmitter to assist in the transmission ofwireless power. For example, the charger chip can be coupled to a CPU ora field-programmable gate array (“FPGA”) in the transmitter. The chargerchip can communicate with the processing unit to determine receivedbeacon signal phases at each antenna on the wireless transmitter,schedule power delivery to client devices, and assist client devices inbeacon scheduling. In some implementations, the charger chip cancommunicate with the processing unit to determine the complex conjugateof the beacon signals received at each antenna. Using the complexconjugates, the charger chip can use one or more antenna ports coupledto off-chip antennas to emit a wireless power signal that approximatelyrecreates the waveform of the beacon signal in the opposite direction.In some implementations, the processing unit instructs a phase shifteron the charger chip to adjust the phase of a transmitted wireless powersignal (also referred to as a “recreated waveform”) based on thereceived beacon signal.

In some implementations, the charger chip operates in industrial,scientific, and medial (ISM) frequency bands such as 2.4 to 2.483 GHz or5.725 to 5.875 GHz. The charger chip can also operate at other ISMfrequencies such as 24.00 GHz or suitable frequencies for transmittingand receiving wireless power. Schematic block diagrams of the chargerchip and other integrated circuitry that function in ISM frequency bandsare disclosed in more detail below with reference to FIGS. 5-12 .

FIG. 5 is a schematic block diagram illustrating components fortransmitting wireless power and receiving communication signals from aclient device. FIG. 5 includes a transceiver 520 a-n, an antenna 535a-n, a phase detector 525 a-n, a phase shifter 530 a-n, a processingunit 510, and a clock source 505 (e.g., a phase-locked loop (PLL) unitor a delayed lock loop (DLL) unit). Here, n represents a natural number,which indicates there can be one or several components (e.g., “n” phasedetectors or “n” antennas).

Collectively, a transceiver, phase detector, and phase shifter can bereferred to as an antenna management unit (AMU) 515 a-n and thesecomponents together form the charger chip along with additionalcircuitry to send and receive signals (e.g., antenna ports to antenna535 a-n, connections to the processing unit 510, connections to theclock source 505, and other circuitry such as grounds). In someimplementations, each transceiver is configured to concurrently transmitan RF power waveform to a client device or multiple client devices. AMUscan also be referred to as antenna modules.

As a broad overview of the AMU 515 a-n, each AMU can receive and amplifyreceived beacon signals from client devices, decode beacon signalsaccording to code controlled by the processing unit 510, detect beaconsignal phases from a client device, send detected phase information tothe processing unit 510, and deliver power to multiple client devices intime-slots according to a priority set by the processing unit 510. Also,each of the AMUs 515 a-n can switch from transmitting a power signal toreceiving a beacon signal or concurrently transmit wireless power andreceive beacon signals (e.g., one antenna port transmitting and anotherantenna port receiving). For example, the transceiver 520 a can switchantenna 535 a between receiving beacon signals and transmitting wirelesspower based on control signals from the processing unit 510.

One or several AMUs can be integrated into the charger chip (e.g., 1-32or more). The manufacturer’s budget and the size of the wireless powertransmitter affect the number of AMUs per charger chip. In general,increasing the number of AMUs per charger chip can increase the amountof power transmitted to clients.

As shown in FIG. 5 , the charger chip is electrically coupled to theprocessing unit 510. The processing unit 510 can be an FPGA, ASIC, orCPU. The charger chip can communicate with the processing unit 510 todetermine the complex conjugate of the beacon signals received at eachantenna 535 a-n. The processing unit 510 can instruct the phase shifter530 a to adjust the phase of a wireless power waveform signal that issent to an antenna to enable the client device to receive a waveform ina particular phase.

The processing unit 510 can assist the AMUs in transmitting wirelesspower. The processing unit 510 can communicate with different clientdevices, manage timing/code synchronization between client devices andAMUs, manage power delivery allocation to different client devices,control power level beacon signals transmitted from a client device(e.g., determine that a beacon signal is weak and require the device toincrease the power used to transmit its beacon signal), and managehandover of client devices from one transmitter to another transmitter.

In some implementations, each AMU can support phase detection andwireless power delivery for multiple client devices simultaneouslythrough Time-Division Multiplexing (TDM). For example, time between twosuccessive phase readings of a beacon signal range from 2 microsecondsto 10 microseconds, which is controlled by the processing unit 510through phase readings to update wireless signals.

Although the processing unit 510, the clock source 505, and the antennas535 an can be located off the charger chip (i.e., physically separatedand integrated through traces), in alternative implementations, theprocessing unit 510, the clock source 505, and the antennas 535 a-n canbe located on the charger chip. For example, the antennas 535 an couldbe integrated into the AMUs 515 a-n for a monolithically integratedchip.

Also, the charger chip can include an on-chip temperature sensor toprotect the charger chip from overheating or damage. For example, theprocessing unit 515 can send a notification to a user or implement ashutdown process if it determines the temperature of the charger chiphas exceeded a certain temperature based on a signal from an on-chiptemperature sensor.

In some implementations, the charger chip transmits RF-based wirelesspower to multiple client devices and receives beacon signals frommultiple client devices. Additionally, in some implementations, thecharger chip transmits RF-based wireless power to multiple receiverswithin a single client device. More details regarding transmittingwireless power to multiple clients or client devices with multiplereceivers are disclosed in U.S. Patent Application No. 15/094963, filedApr. 8, 2016, titled “WIRELESS CHARGING WITH MULTIPLE POWER RECEIVINGFACILITIES ON A WIRELESS DEVICE,” which is hereby incorporated byreference in its entirety.

Moving to a more detailed description of the AMU 515 a-n, FIG. 6 is ablock diagram illustrating a schematic diagram of an AMU. FIG. 6includes a phase-locked loop (PLL), phase shifter and phase detectorblock, and two power amplifiers (e.g., to increase the gain of receivedbeacon signals), as well as a transceiver switch (e.g., to switchbetween receiving a beacon signal and sending a power signal), and anoff-chip antenna. Although a PLL is shown in FIG. 6 , a delay-lockedloop (DLL) can be used in lieu of the PLL. A nominal 3.3 or lower DCpower can be used to power each AMU.

FIG. 7 is an example integrated circuit charger chip with multiple AMUsfor transmitting wireless power and receiving beacon signals. On theleft side of FIG. 7 , digital control signals can be received from aprocessing unit (e.g., an FPGA). The processing unit can instructdifferent AMUs 515 a-n to transmit different wireless power signals. Theprocessing unit can provide signals, can include information about thephase shift to be applied to a waveform (e.g., 0-180° shift, which maybe used for modulation/coding), whether to bypass a phase-locked loop(PLL), the control signals for transceivers (e.g., to switch atransceiver from receive to transmit), and the serial interface signals(e.g., signals to the registers for the different transceivers andantennas). For example, the incoming signal can indicate to phase shifta particular power signal sent to a particular AMU (e.g., 515 a), andthe data can be stored in register 715. A clock source (e.g., 2.4 GHz)is used to synchronize signals going to the AMUs 515 a-n.

FIG. 8 is another schematic of a charger chip. As shown in FIG. 8 , anAMU 515 a can be connected to a CPU coupled to memory. The CPU cancommunicate with a processing unit via a low-voltage differentialsignaling (LVDS) system (e.g., a TIA/EIA-644) over a serial data line.The processing unit can also be coupled to multiple antenna boards.Antenna boards are described in more detail in U.S. Pat. Application No.15/289,117 titled “ANTENNA CONFIGURATIONS FOR WIRELESS POWER ANDCOMMUNICATION, AND SUPPLEMENTAL VISUAL SIGNALS,” filed on Oct. 7, 2016,which is incorporated by reference herein in its entirety.

In some implementations, each charger chip is connected to a DC-DCconverter (as shown in FIG. 8 ), which can step down (e.g., decrease)the voltage supplied to each AMU. For example, the motherboard of aclient device can supply 12 V of power, but each charger chip withseveral AMUs may operate on 1.8 volts, so the DC-DC converter convertsthe 12 V to 1.8 V.

While not shown in FIG. 8 , the charger chip can be part of a printedcircuit board (PCB). The PCB can have several (e.g., 2-2000) chargerchips each with several AMUs. For example, if a charger chip has fourAMUs, it can drive and receive from four antennas. If there are 16charger chips, then there can be 64 antennas on a single PCB. Theprocessing unit can send instructions to each AMU on the charger chip.For example, a CPU can control the phase shifter, which changes thephase of the outgoing power signal to an antenna. The amplifier canincrease (e.g., amplify) the signal strength. Also, the PLL can keep allthe AMUs synchronized.

FIG. 9 illustrates an alternative implementation of an AMU on a chargerchip. In particular, FIG. 9 discloses an implementation of a chargerchip that operates digitally as compared to in analog as described abovein FIGS. 5-8 . The transceiver switch 910 can be configured to switch anantenna from receiving a beacon signal to transmitting wireless power.If the transceiver switch 910 is set to receive, the received signal canbe amplified in an amplifier 945 (e.g., a low noise amplifier) and witha mixer block 940 (e.g., converts a signal from one frequency to anotheror modulates/de-modulates a signal). Then the signal can be convertedfrom an analog signal to a digital signal using an analog-to-digitalconverter (ADC) 935. After the conversion, the signal is sent to adigital processing unit 930 (e.g., to determine the phase or otherinformation about the signal). The digital processing unit 930determines whether to send a power signal to the client, and if so, howmuch power to send and the phase of the signal. That signal goes to adigital-to-analog (DAC) converter 925, into mixer block 920, into apower amplifier 915 to increase the strength signal, and then thetransceiver switch 810 is switched to send the power signal to a client.A clock source 905 can synchronize the signals transmitted and received.In some implementations, operating the AMU in the digital domain reducesthe charger chip footprint as compared to analog domain charger chip.Also, in some implementations, operating the AMU in the digital domainreduces power consumption compared to operating the AMU in the analogdomain.

The charger chip can include additional features on the chip. In someimplementations, each AMU on the charger chip includes a received signalstrength indicator (RSSI) in a beacon detection path (e.g., coupled tothe antenna port for antennas 535 a). The RSSI reading helps todetermine if the received beacon is below or above a threshold (e.g., aminimum power level). Based on the RSSI values, the charger chip can setor reset a flag-bit that indicates the quality of the beacon signal.More generally, RSSI threshold values are used to determine whichantennas and AMUs to turn on or turn off to increase the efficiency ofwireless power delivery. By using the RSSI threshold values the powerconsumption of the charger can be reduced, thereby increasing theefficiency of the charger.

FIG. 10 is an example diagram of beacon timing and power delivery for acharger chip. In some implementations, beacon timing is divided into 32time slots where each client sends a beacon in one time slot, and it ismodulated with that client device’s unique phase modulation code (e.g.,1101001101...for client 0), using, e.g. BPSK, DPSK, QPSK, or othermodulation schemes. Also, power delivery can be divided into time slots.For example, power is sent to one client during each time slot, aprocessing unit implements a schedule table (e.g., stored in memory) tocontrol the time slot(s). As shown in FIG. 10 , a total time cycle(between delivering power and phase detection from beacons) can be 100ms, wherein phase detection is approximately 64 ps. More detailsregarding beacon timing and power delivery are disclosed in U.S. Pat.Application 14/956,673, filed Dec. 02, 2015, titled “TECHNIQUES FORENCODING BEACON SIGNALS IN WIRELESS POWER DELIVERY ENVIRONMENTS,” whichis hereby incorporated by reference in its entirety.

FIG. 11 is an example of an AMU that receives a request to send power toa client device and receives the corresponding phase for a power signalto send to the client device. For example, a digital processing unitcomputes the phase table shown in FIG. 10 (e.g., the phase for sendingpower to client 0 or client 1), and in response the AMU uses a phaseshifter, synchronization signal from a clock, and amplifier to send apower signal to a client with a corresponding phase. In someimplementations, the AMU can dynamically assign different client devicesto different transmitters in the same area. In some implementations, theclient devices can send a beacon signal more than once-e.g., thephase-coding scheme allows for a possibility that all client devicessend beacon signals in all time slots-with the transmitter decidingwhich client device it wants to phase-measure in each time slot.

FIG. 12 is an example of a power delivery table for clients from anantenna management unit on a charger chip. As shown in FIG. 11 , acharger chip can have a table of client modulation codes and a powerdelivery table. The tables allow a charger chip to know which client topower, when to power it, and how much power to transmit. In general,FIG. 12 shows how a signal can be modulated (e.g., table for clientmodulation codes) and how a client can be powered (e.g., power deliverytable).

Client Chip Technology

As discussed in FIGS. 1-4 , a client device can include a receiver thatenables the client device to receive wireless power and transmit beaconsignals. To receive wireless power and transmit beacon signals, thereceiver can include an IC (also referred to as the “client chip”). Insome implementations, the client chip can receive, rectify, and convertRF wireless power into DC voltage/current. The client chip can use theDC voltage/current to power the client device physically coupled to theclient chip, or it can use the voltage/current to store power in abattery physically coupled to the client device. The client chip canalso transmit a beacon signal to the wireless transmitter (transmitter101 in FIG. 1 ).

In some implementations, the client chip communicates with the clientdevice to customize power delivery. For example, the client chip storesthe client device’s power management protocol in memory on the clientchip and delivers power according to client device’s power managementprotocol. In other implementations, the client chip can directly power abattery or component of the client device without using the clientdevice’s power management integrated circuit (PMIC). Additionally, insome implementations, the client chip sends power directly to the clientdevice PMIC.

The client chip can be composed of semiconductor material, such asSilicon, GaAs, Silicon on an insulator (SOI), or GaN. Manufacturers canfabricate the client chip using semiconductor material and processingmethods such as doping, ion implantation, etching, deposition of variousmaterials, photolithographic patterning, dicing, and/or packaging. Insome implementations, the client chip is an ASIC. One or more ASICclient chips can be integrated into the receiver 103 shown in FIG. 1 .

In some implementations, the client chip operates in ISM frequency bandssuch as 2.4 to 2.483 GHz or 5.725 to 5.875 GHz. The client chip can alsooperate at other ISM frequencies such as 24.00 GHz or frequenciessuitable for wireless power transmission.

In addition to receiving wireless power, the client chip can communicatewith other integrated on the device client for supplementaryfunctionality. For example, antennas can be configured to communicateusing a wireless standard (e.g., WiFi, IEEE 802.11, ZigBee™, Bluetooth™) and transmit beacon signals. In some implementations, the client chipcan use an antenna to communicate via Bluetooth™, WiFi, ZigBee™, orother wireless communication protocols. In general, instructions forcommunicating or transmitting beacon signals can be stored in memory,and these instructions can be executed by the CPU.

Moving to FIGS. 13A-13C, the Figures together show an example schematicdiagram of a circuit for the wireless power receiver. The schematicdiagram is spread over FIGS. 13A, 13B, and 13C as shown with connectingpoints “A” and “B” in FIG. 13A; “A,” “B,” “C,” and “D” in FIG. 13B; and“C” and “D” in FIG. 13C. As a broad overview, the circuit includeselements such as capacitors, op-amps, inductors, lead wires, andgrounds. These components can be varied to meet design specifications.For example, some capacitors can have a capacitance of 1 microfarad or 1picofarad, and inductors can have an inductance of 1 millihenry.Voltages in the circuit can be 0 to 5 volts (or more) with a typical 3.3volts to open a gate to send a beacon signal. Resistors can have 20 to200 Ohms (or more) resistance ratings. But overall, actual values ofcomponents shown in FIGS. 13A-13C depend upon the implementation detailsand design constraints.

Starting on the left side of FIG. 13A, an antenna 1305 receives wirelesspower or data. Although one antenna is shown in FIG. 13A, severalantennas can be included in the circuit, where the antennas would beconnected to similar components as the antenna 1305. Once the antenna1305 receives power, the wireless power moves to sensing unit 1310.Sensing unit 1310 senses if an antenna is receiving power. A sensingunit 1310 can be a directional coupler or other RF detector (alsoreferred to as a “detection unit”). As shown in FIG. 13A, an input unit1325 is connected or coupled to the sensing unit 1310. The input unit1325 may be simple logic or circuitry configured to send informationregarding the received wireless power to another part of the system suchas the CPU.

Regarding sensing information for wireless power, the sensing unit 1310receives a small portion of the wireless power and notifies the wirelessdevice that power has been received. The CPU in the wireless device canuse the sensed wireless power information to determine which antennasare receiving power and how much power is received. In some embodiments,the CPU can store this data in memory and send it to a transmitter,database, or cloud storage device for further analysis (e.g., todetermine which antennas are generally better for receiving power). As asample use of sense information, the transmitter can determine whichtransmitting antennas are efficiently sending power to which receivingantennas based on sense information, and the transmitter CPU can usethis information to optimize the transmission of wireless power. In someimplementations, a processing unit on the client device can receivesensed power information and use it to increase (e.g., optimize) theamount of power received at the client device. For example, a clientdevice can store instructions in memory that when executed by aprocessor cause the client device to only receive wireless power fromantennas that are receiving wireless power above a threshold (e.g., aminimum voltage). In such an example, the client device can shut downantennas that are receiving power below a threshold or dedicate theseantennas below a threshold to transmitting beacon signals. As anotherexample, the processor can execute an algorithm that determines whichantennas are receiving more power than other antennas (e.g., rankingalgorithms), and use this algorithm to increase (e.g., optimize) theamount of power received by deactivating some antennas or dedicatingsome antennas to transmitting a beacon signal. The processor can sendcontrol signals to active, deactivate, or switch an antenna from beaconsignaling to transmitting power.

After sensing that RF power is received at antenna 1305, the circuit inFIG. 13A determines a path for the power. As shown in FIG. 13A,switching unit 1315 can switch the antenna from a communication orbeacon mode to rectifying mode by applying a voltage to the switchingunit 1315 (“RF_switch_RECTIFIER,” “V2”). As V2 is applied to theswitching unit 1315, the power is directed towards “J2” where it entersan RF rectifier 1320. A switching unit 1315 can be referred to as acontrol unit and it can be implemented in an integrated circuit or on anASIC. The RF rectifier 1320 converts the RF power to DC, and the DCpower can directly enter a battery.

Also, the circuit in FIGS. 13A-C can use antenna 1305 to communicate orsend the beacon signal. As shown in FIG. 13A, if voltage (e.g., V1 by“RF SWITCH COMM”) is applied to switching unit 1315, the circuit cancommunicate using a known signal type (e.g., WiFi, Bluetooth™, ZigBee™).The “A” point on FIG. 13A shows where communication signals aretransmitted and received. Additionally, if voltage (e.g., V3) is appliedto switching unit 1315, the beacon signal can be transmitted fromantenna 1305 as described in more detail below with respect to FIG. 13C.

Moving to FIG. 13B, the circuit can send communication from point “A” topoint “C”. Although not shown in FIG. 13B, point “C” is connected to anintegrated circuit for communication such as communicate via Bluetooth™,WiFi, ZigBee™, or other wireless communication protocols. Before thesignal is sent to the respective communication chip, a filter can removethe data from the wireless power signal.

Staying with FIG. 13B, a central control unit (e.g., a processor) cansend a pulse and amplitude enabling signal (“PA_Enable”) to enable abeacon signaling sequence. Once the “CLOSED” portion of circuit 13Bopens (as shown in the middle-upper portion of FIG. 13B), a voltagereaches two op-amps 1330. The two-op amps 1330 amplify the beacon signalcoming from “D”. A CPU or ASIC can generate the beacon signal that comesfrom “D”. After the beacon signal is amplified, antenna 1305 transmitsit.

As shown in FIG. 13C, another switch 1335 can activate the beaconsignaling path shown in FIG. 13C. A CPU can send an “RF Switch Beacon”signal into switch 1335, and switch 1335 can flip and cause “RF_P” toenter the circuit. “RF_P” can be a pulse with a beacon signal.

Overall, FIGS. 13A-13C describe a general integrated circuit schematicfor using an antenna to receive power, communicate information, andtransmit a beacon signal. As disclosed below, FIGS. 14, 15, 16, and 17describe specific implementations of the integrated circuit described inFIGS. 13A-13C with various embodiments. Specifically, FIGS. 14 and 15are block diagrams of an ASIC for receiving wireless power. FIGS. 16 and17 disclose an ASIC that is electrically coupled to a CPU in a wirelessdevice.

FIG. 14 is an example of a block diagram illustrating a client chip usedin a client device for receiving wireless power, transmitting beaconsignals, or transmitting communication signals. The client chip caninclude: “N” RF detectors (where “N” is a natural number, e.g., 4), “N”RF rectifiers, an MPP (maximum power point tracking “MPPT”, alsoreferred to as the “MPP”) for each “N” RF rectifier, an N-channel analogmultiplexer (MUX), a buck-boost converter, an analog to digitalconverter (ADC), antenna 1404 for sending beacon signals, “N” antennainputs 1406 for receiving wireless power, a register bank, groundconnections, a frequency comparer 1408, and input/output connections. Asillustrated, an RF rectifier can be coupled to an MPP loop to optimizepower delivery. For example, the MPPT loop can communicate with abuck-boost converter to provide the client with constant voltage/currentin an efficient manner. Additionally, as shown in FIG. 14 , one antennacan be transmitting a beacon signal as another antenna concurrentlyreceives RF power. Also, while not illustrated in FIG. 14 , a clientdevice can receive a sensed RF value from an RF detector and based onthe received RF power being low (e.g., less than 0.02 watts), the clientdevice (e.g., using a CPU) can switch the antenna off (e.g., with aswitch connected to the antenna).

Also, the client chip receives a strength signal indicator (RSSI, orother similar signal) via the received signal and ADC. The RSSI canserve multiple purposes such as identifying clients that are notreceiving enough power to rectify a significant amount of DC, oridentifying clients who are receiving a very high power and shouldprobably have their duty cycle reduced. In general, the RF detector,MPP, N-MUX, ADC, and RSSI components communicate with the CPU of aclient device (not shown) to determine how to increase (e.g., optimize)power received by the client chip.

Although a buck-boost converter is shown in FIG. 14 , other converters,such as a flyback converter can be used to optimize the power delivery.Also, although the client chip is physically coupled to “N” number ofantennas, and more antennas generally means the chip can receive morepower, the number of antenna ports may be reduced to lower cost of chipdesign (e.g., optimize). Also, to optimize power delivery to the clientdevice, short traces can be used and the number of resistors can belimited to lower the loss of power (e.g., improve efficiency).Additionally, antennas should be placed close to RF rectifiers to reduceimpedance. Also, if all antennas emit the beacon signal then spacing canvary between antennas because the transmitter can detect the beaconsignal from all antennas and send power back to all antennas.Alternatively, if only one antenna emits the beacon, the other antennascan be within ¼ wave length (~3 cm) of the beacon emitting signal.

Also, FIG. 14 includes a register bank. The register bank can storevalues such as a received RSSI value, MPP value, RSSI channel select, PAgain control, PA source select, and prescaler divider control. Thesevalues can be saved in the register and can be used by a processor.Additionally, a processor can access the register bank and send thestored values to another device or network.

Similar to FIG. 14 , FIG. 15 is another example block diagramillustrating a schematic of a client chip. The client chip receives,rectifies, and converts RF power into DC voltage/current. The clientchip can use the DC voltage/current received from a client chip to powerthe client, or it can use the DC voltage/current to store power in abattery. Also, a client chip can couple to a single antenna 1505 (e.g.,to transmit the beacon signal), and couple to multiple antennas 1510 a-n(e.g., four antennas to receive power). The client chip includes an RFrectifier 1530 a-n for each antenna, a maximum power point tracking(MPPT, or also referred to as the “MPP”) 1535 a-n loop, a buck-boostconverter 1540, a transceiver switch 1560, an RF detector 1525, a PLL1545, and a memory 1550. In general, multiple client chips can be placedin a single wireless device as shown in FIG. 1 .

In some implementations, the client chip transmits a beacon signal, andthe beacon signal includes information used to compute the location ofthe client, as described above in FIG. 1 . The client chip can transmitbeacon signaling to the wireless charger (e.g., in wireless charger 101in FIG. 1 ) using an RF signal input, PLL 1545, power amplifier 1520,transceiver switch 1560, and antenna 1505. The beacon signal encodingprocess and algorithm may be as described in the applicant’s U.S.Application No. 14/956,673, filed Dec. 2, 2015, titled TECHNIQUES FORENCODING BEACON SIGNALS IN WIRELESS POWER DELIVERY ENVIRONMENTS, whichis hereby incorporated by reference in its entirety.

In some implementations, the memory 1550 on the client chip stores thepower management policy for the client device (e.g., the PMICinstructions). In these implementations, the client chip can supplypower directly to the client device (e.g., in the battery or into theclient device’s system). Alternatively, a client device may have aproprietary PMIC, and the client chip may be coupled to the PMIC. Inthese implementations, the client chip supplies power according to thespecification provided by the manufacturer of the PMIC, and the client’sPMIC handles the management of this power (e.g., pins and traces can beused to allow the client chip and PMIC to communicate and transferpower).

Although not shown in FIGS. 14 or 15 , the client chip can support awide range of applications with different power requirements startingfrom several hundred milli-watts (mW) up to several watts of power.Also, the client chip can include an on-chip temperature sensor toprotect the chip from overheating or damage.

Moving to FIG. 16 , FIG. 16 is an example of a power receiving client.As shown in solid lines, RF signals combine right after being receivedby antennas and then the power is rectified. The efficiency of thisalternative can depend on if there is constructive or deconstructiveinterference when combining RF power after the antennas receive powersignals. Another option, as shown with broken lines, RF signals arecombined after the power is rectified. The receiver can employ one oftwo ways to achieve parallel combination: either by combining thesignals at RF in the front end of the client or by combining the signalsat DC after conversion. FIG. 10 also includes a data communications unit(bottom left), which can be used to communicate with a network ortransmitter over WiFi or Bluetooth™.

FIG. 17 is another, similar example of a power receiving client withother client technology. This example is different than the examplesabove because, in part, this client includes a Bluetooth™ chip. As shownin FIG. 17 , the client can have antennas that receive power and data(e.g., Bluetooth™ data). In some implementations, the power and datasignals can be at the same frequency, and the antennas of the client maypick up both a power signal and a data signal. In order to separatethese signals, as shown in FIG. 17 , the client can include a filter toseparate power from data even if the signal is the same frequency. Afterthe signal is filtered, power can be sent to the RF rectifier andconverted to DC power. Additionally, a client can communicate viaBluetooth™, WiFi, ZigBee™, or other wireless communication protocols.

In some implementations, a data power filter may be used to separate thesignals. Methods and systems for separating or filtering these types ofsignals is described in the applicant’s U.S. Pat. Application No.14/926,014, filed Oct. 29, 2015, titled “TECHNIQUES FOR FILTERINGMULTI-COMPONENT SIGNALS,” which is hereby incorporated by reference inits entirety. Data signals can be sent to the Bluetooth™ chip forappropriate transmission. Similar to other examples of chips and clientsdescribed above, this client can use one or more channels in parallel toreceive RF power and convert it into DC using the MPPT algorithm foroptimization. In some implementations, DC power can be used to charge abattery on the client device. This client is also capable of sending abeacon signal at 2.4 GHz because it has a PLL/Frequency Synthesizer andpower amplifier integrated into it, which can be used to send a beaconwith the client’s location to a wireless charger. The frequency ofoperation is not limited to just 2.4 GHz but can also operate in otherISM frequency bands or frequency bands outside of ISM.

Also, although not shown in FIG. 17 , WiFi technology can be used in asimilar method described in the example above. For example, if a clienthas a WiFi chip and a client chip, a filter can be used on the clientchip to separate the data signal from the power signal even if thesignals are sent at the same frequency.

In addition to the components disclosed in FIGS. 13A-13C and FIGS. 14-17for the client chip, the client chip can include additional featuressuch as a cold start. A cold start can be software stored on the clientchip or stored on the client device that enables the client device tooperate in low power mode until RF power is available to bring-up thereceiver again autonomously. For example, when the battery for a clientdevice is dead, the client chip can enter a cold start mode until thebattery has enough power to power the client device.

Conclusion

Unless the context clearly requires otherwise, throughout thedescription and the claims, the words “comprise,” “comprising,” and thelike are to be construed in an inclusive sense, as opposed to anexclusive or exhaustive sense; that is to say, in the sense of“including, but not limited to.” As used herein, the terms “connected,”“coupled,” or any variant thereof, means any connection or coupling,either direct or indirect, between two or more elements; the coupling ofconnection between the elements can be physical, logical, or acombination thereof. Additionally, the words “herein,” “above,” “below,”and words of similar import, when used in this application, shall referto this application as a whole and not to any particular portions ofthis application. Where the context permits, words in the above DetailedDescription using the singular or plural number may also include theplural or singular number respectively. The word “or,” in reference to alist of two or more items, covers all of the following interpretationsof the word: any of the items in the list, all of the items in the list,and any combination of the items in the list.

The above Detailed Description of embodiments of the disclosure is notintended to be exhaustive or to lim it the teachings to the precise formdisclosed above. While specific embodiments of, and examples for, thedisclosure are described above for illustrative purposes, variousequivalent modifications are possible within the scope of thedisclosure, as those skilled in the relevant art will recognize. Forexample, while processes or blocks are presented in a given order,alternative embodiments may perform routines having steps, or employsystems having blocks, in a different order, and some processes orblocks may be deleted, moved, added, subdivided, combined, and/ormodified to provide alternative or subcombinations. Each of theseprocesses or blocks may be implemented in a variety of different ways.Also, while processes or blocks are, at times, shown as being performedin a series, these processes or blocks may instead be performed inparallel, or may be performed at different times. Further, any specificnumbers noted herein are only examples: alternative implementations mayemploy differing values or ranges.

The teachings of the disclosure provided herein can be applied to othersystems, not necessarily the system described above. The elements andacts of the various embodiments described above can be combined toprovide further embodiments.

These and other changes can be made to the disclosure in light of theabove Detailed Description. While the above description describescertain embodiments of the disclosure, and describes the best modecontemplated, no matter how detailed the above appears in text, theteachings can be practiced in many ways. Details of the system may varyconsiderably in its implementation details, while still beingencompassed by the subject matter disclosed herein. As noted above,particular terminology used when describing certain features or aspectsof the disclosure should not be taken to imply that the term inology isbeing redefined herein to be restricted to any specific characteristics,features, or aspects of the disclosure with which that terminology isassociated. In general, the terms used in the following claims shouldnot be construed to limit the disclosure to the specific embodimentsdisclosed in the specification, unless the above Detailed Descriptionsection explicitly defines such terms. Accordingly, the actual scope ofthe disclosure encompasses not only the disclosed embodiments, but alsoall equivalent ways of practicing or implementing the disclosure underthe claims.

While certain aspects of the disclosure are presented below in certainclaim forms, the inventors contemplate the various aspects of thedisclosure in any number of claim forms. For example, while only oneaspect of the disclosure is recited as a means-plus-function claim under35 U.S.C. § 112(f), other aspects may likewise be embodied as ameans-plus-function claim, or in other forms, such as being embodied ina computer-readable medium. (Any claims intended to be treated under 35U.S.C. § 112(f) will begin with the words “means for”). Accordingly, theapplicant reserves the right to add additional claims after filing theapplication to pursue such additional claim forms for other aspects ofthe disclosure.

What is claimed is:
 1. A method comprising: receiving, via a pluralityof antennas, a wireless signal from a device positioned in a wirelesssignaling environment; sensing a power of the wireless signalrespectively received via at least two antennas of the plurality ofantennas; transducing energy of the wireless signal to an electriccurrent; and adjusting a voltage of the electric current according tothe sensing.
 2. The method of claim 1 further comprising transmitting,using at least one antenna of the plurality of antennas, a firstwireless signal to the device.
 3. The method of claim 2 furthercomprising generating the first signal prior to the transmitting.
 4. Themethod of claim 2, wherein receiving the wireless signal comprisesreceiving a second wireless signal from the device in response to thetransmitting.
 5. The method of claim 1 further comprising determining,based on the sensing, that a received power of the wireless signal of afirst antenna of the at least two antennas is greater than a receivedpower of the wireless signal of at least a second antenna of the atleast two antennas.
 6. The method of claim 5, wherein the wirelesssignal includes a wireless power signal, the method further comprisingswitching, in response to the determining, the first antenna, or the atleast a second antenna, from receiving the wireless power signal fromthe device to receiving a signal encoding data from the device.
 7. Themethod of claim 5 further comprising switching, in response to thedetermining, the first antenna, or the at least a second antenna, fromreceiving the wireless signal from the device to transmitting anotherwireless signal to the device.
 8. The method of claim 5 furthercomprising stopping, in response to the determining, transducing energyof the wireless signal received via the first antenna or the at least asecond antenna.
 9. The method of claim 1 further comprising charging anenergy storage device using the electric current.
 10. The method ofclaim 1 further comprising powering an electronic device using theelectric current.
 11. A device comprising: a receiver including aplurality of antennas, and configured to receive a wireless signal froma wireless device positioned in a wireless signaling environment; meansfor sensing a power of the wireless signal received via a first antenna,and at least a second antenna, of the plurality of antennas; means fortransducing energy of the wireless signal to an electric current; andmeans for adjusting a voltage of the electric current according to thepower of the wireless signal.
 12. The device of claim 11 furthercomprising means for transmitting a first wireless signal to thewireless device using at least one antenna of the plurality of antennas.13. The device of claim 12 further comprising means for generating thefirst wireless signal prior to the first wireless signal beingtransmitted.
 14. The device of claim 12, wherein the receiver isconfigured to receive the wireless signal as a second wireless signal inresponse to the first wireless signal being transmitted.
 15. The deviceof claim 11 further comprising means for determining, based on the powerof the wireless signal, that a power of the wireless signal received viathe first antenna is different from a power of the wireless signalreceived via the at least a second antenna.
 16. The device of claim 15,wherein the wireless signal includes a wireless power signal, the devicefurther comprising means for switching, in response to the power of thewireless signal received via the first antenna being determined to bedifferent from the power of the wireless signal received via the atleast a second antenna, the first antenna, or the at least a secondantenna, from receiving the wireless power signal from the wirelessdevice to receiving a signal encoding data from the wireless device. 17.The device of claim 15 further comprising means for switching, inresponse to the power of the wireless signal received via the firstantenna being determined to be different from the power of the wirelesssignal received via the at least a second antenna, the first antenna, orthe at least a second antenna, from receiving the wireless signal fromthe wireless device to transmitting another wireless signal to thewireless device.
 18. The device of claim 15 further comprising means forstopping, in response to the power of the wireless signal received viathe first antenna being determined to be different from the power of thewireless signal received via the at least a second antenna, transductionof the energy of the wireless signal received via the first antenna orthe at least a second antenna.
 19. The device of claim 11 furthercomprising at least one of: means for charging an energy storage deviceusing the electric current; and means for powering an electronic deviceusing the electric current.
 20. One or more non-transitory computerreadable media having stored thereon program instructions which, whenexecuted by at least one processor, cause a machine to: sense a power ofa wireless signal received from a wireless device via a plurality ofantennas; and adjust, according to the sensed power of the wirelesssignal, a voltage of an electric current generated by transduction ofenergy of the wireless signal.